Ancestry and taxonomy

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1. What ancestry and taxonomy each tell us

Ancestry determines how much of each species a character inherits. Taxonomy determines how closely related those inherited species are when two characters are compared.

For example, a character can be 80% Fox and 20% Wolf. Those numbers come from their parents and the recipes of the species in their family tree. If Fox and Wolf share a taxonomic family, that relationship helps determine compatibility. It does not turn some of the Fox ancestry into additional Wolf ancestry. The character remains 80% Fox and 20% Wolf.

There are three different kinds of percentage in this guide:

Percentage	Question it answers	Example
Species composition	How much of this character comes from each species?	80% Fox, 20% Wolf
Taxonomy compatibility	How closely related are the species represented in two characters, accounting for their shares?	A family match has a default score of 25% for that species pair
Combined compatibility	How strongly do species overlap and taxonomy support this pairing?	35% overlap and 26.35% taxonomy combine to 52.1275% before other modifiers

These are gameplay inheritance and compatibility rules, not a measurement of real DNA or real-world reproductive probabilities. Examples below use the default taxonomy scores and explicitly assigned example classifications.

From ancestry to compatibility

The percentages stay attached to their species throughout this process. Taxonomy supplies a comparison score for each pair of ingredients.

2. Start with the species recipe

A base species is a purebred species with no hybrid members to expand. A hybrid recipe names member species with relative weights. Positive weights normalize to the shares used below; the entered weights do not need to total 100. A member can itself be a hybrid, so its share may need further expansion.

Species kind	Definition	Example recipe
Purebred	Stands on its own	Fox = 100% Fox
True Hybrid	Has exactly two direct member species	Foxwolf = 60% Fox + 40% Wolf
Composition Hybrid	Has three or more direct member species	Wildmix = 50% Foxwolf + 25% Wolf + 25% Lynx

These kinds describe the species recipe. An individual carrying a purebred species label can still have mixed ancestry, as the next section explains.

Expanding a nested recipe

Wildmix contains 50% Foxwolf. Foxwolf is itself 60% Fox and 40% Wolf, so multiply the percentages along that branch:

Fox through Foxwolf  = 50% × 60% = 30%
Wolf through Foxwolf = 50% × 40% = 20%
Wolf directly       = 25%
Lynx directly       = 25%

Wildmix = 30% Fox + 45% Wolf + 25% Lynx

Expand the Wildmix recipe

Wolf appears through two branches, so both contributions are added. Foxwolf does not remain an additional slice after it has been expanded: its entire 50% is already accounted for by Fox and Wolf.

The same multiplication applies at every nesting level. All valid recipe shares together account for 100% of the resulting composition.

3. Inherit the parents’ actual compositions

For a character with two parents, the rule is:

Child's share of a species
    = half of the mother's share + half of the father's share

Use each parent’s inherited composition, including their ancestors. A parent’s selected species name alone does not determine what they pass on.

The calculation has these starting and fallback rules:

Character situation	Source of the composition
Founding ancestor	The selected species recipe
Descendant with two parents	50% of each parent’s composition
Descendant with one known parent	100% of the known parent’s composition
Character without parents	The selected species recipe

The one-parent rule is a fallback for incomplete parentage. It does not invent an unknown second parent’s species. An actual parent whose species has no taxonomy is different: that parent’s species contribution is still known and still occupies its normal share.

Founding hybrids keep their declared recipes. A founder declared as 60% Fox and 40% Wolf remains 60/40 even if its origin story names one Fox and one Wolf ancestor. Ordinary descendants inherit from that founder’s 60/40 composition.

A two-character family tree

We will compare two characters, Aster and Briar:

Aster and Briar’s family tree

The four parents shown above are founders using the recipes already described. Aster’s mother is pure Fox and the father is 60% Fox / 40% Wolf. Briar’s mother is Wildmix and the father is pure Lynx.

Aster’s percentages are:

Species	Half of mother’s composition	Half of father’s composition	Aster
Fox	50%	30%	80%
Wolf	0%	20%	20%
Total	50%	50%	100%

Briar’s percentages are:

Species	Half of mother’s composition	Half of father’s composition	Briar
Fox	15%	0%	15%
Wolf	22.5%	0%	22.5%
Lynx	12.5%	50%	62.5%
Total	50%	50%	100%

If Aster and Briar have a child, its Fox share is (80% + 15%) ÷ 2 = 47.5%. The same calculation gives 21.25% Wolf and 31.25% Lynx.

The parents’ compatibility score does not change these inheritance shares. Compatibility affects breeding calculations; the child’s composition follows the parental averaging rule.

Why grandparents are not added a second time

Each parent’s composition already includes the grandparents. A contribution travelling through two successive parent-child links is multiplied by one-half twice. A grandparent who is 60% Fox therefore contributes 25% × 60% = 15% Fox through that one path.

Distance along one ancestral path	Fraction of that ancestor’s composition reaching the character
Parent	50%
Grandparent	25%
Great-grandparent	12.5%
Four generations back	6.25%

These figures assume two known parents at each intervening generation. If the same species arrives through several paths, add those contributions. If the same ancestor occurs in several branches, each legitimate path contributes; their already calculated composition can be reused without losing any shares.

The character’s selected label also adds no extra share. Calling Aster “Fox,” “Foxwolf,” or a composition species does not change the inherited 80/20 result.

4. Attach taxonomy to each inherited species

Purebred species can have their own classification. True hybrids and composition hybrids derive taxonomy from the purebred species inside their expanded recipes. A hybrid has no separate direct taxonomy that overrides its members.

The ranks run from broad to specific:

Taxonomy ranks

For our worked examples, assume the classifications below have been assigned. Broader ranks are omitted from this diagram because the shared order is already the closest match between the two families.

Shared classifications in the example

Fox and Wolf share a family but have different genera. Fox and Lynx, and Wolf and Lynx, share the order but have different families.

Use the closest shared rank once for each species pair. A family match does not also add the order, class, phylum, and kingdom scores.

Closest shared rank	Default taxonomy score for the pair
Taxonomic species	90%
Genus	50%
Family	25%
Order	10%
Class	5%
Phylum	2%
Kingdom	1%
Domain only	0%
No shared rank or no usable classification on either side	0%

For example, two different Fox species classified in the same genus would receive a 50% pair score. Our Fox and Wolf receive 25%; our Fox and Lynx receive 10%. These are default game scores, not fractions of shared DNA.

Species identity and taxonomic species are different

Two separately defined game species can share the same taxonomic species classification. They still occupy separate slices of a character’s composition. Their exact-species overlap is zero unless they share an actual base species, but their taxonomy pair score can be 90%.

Matching display names alone does not establish either identity or a shared classification. Two independently named “Fox” species need not be the same species or share the same taxonomy.

Aster’s 80% Fox and 20% Wolf could be described as 100% belonging to the shared canid family. That is a grouping of existing shares, not another 100% to add to the composition. Broader and narrower ranks describe overlapping groups.

5. First comparison: exact species overlap

Compare the amount of each base species that both characters carry. For each species, take the smaller share, then add those shared amounts.

Species	Aster	Briar	Shared amount
Fox	80%	15%	15%
Wolf	20%	22.5%	20%
Lynx	0%	62.5%	0%
Total	100%	100%	35% species overlap

Aster’s extra 65 percentage points of Fox cannot overlap with Fox that Briar does not have. Briar’s Lynx cannot contribute to exact-species overlap with Aster, although its taxonomy can still matter in the next comparison.

Identical compositions have 100% overlap. Disjoint compositions have 0% overlap. The overlap is symmetric: comparing Aster to Briar gives the same result as comparing Briar to Aster.

6. Second comparison: taxonomy weighted by both compositions

Compare every inherited species on one side with every inherited species on the other side. Multiply three values for each pair:

Pair contribution = Aster's species share
                  × Briar's species share
                  × closest-shared-rank score

Use fractions while calculating: 80% is 0.80, 22.5% is 0.225, and 25% is 0.25. Convert the result back to a percentage at the end.

For our classifications, the pair scores are:

Aster’s species / Briar’s species	Fox	Wolf	Lynx
Fox	90% — same taxonomic species	25% — family	10% — order
Wolf	25% — family	90% — same taxonomic species	10% — order

Now apply the actual ancestry shares:

Pair	Calculation using fractions	Contribution to taxonomy score
Fox × Fox	0.80 × 0.15 × 0.90	10.8 percentage points
Fox × Wolf	0.80 × 0.225 × 0.25	4.5 percentage points
Fox × Lynx	0.80 × 0.625 × 0.10	5 percentage points
Wolf × Fox	0.20 × 0.15 × 0.25	0.75 percentage points
Wolf × Wolf	0.20 × 0.225 × 0.90	4.05 percentage points
Wolf × Lynx	0.20 × 0.625 × 0.10	1.25 percentage points
Total	0.2635	26.35% taxonomy compatibility

There are six pairs because Aster has two species and Briar has three. Fox × Wolf and Wolf × Fox are both included: they involve different portions of these characters. Swapping the characters reverses the table but preserves the total.

One way to interpret the weighting is to choose an ingredient from each character at random, with larger shares more likely to be chosen. The taxonomy score is the average relatedness score of those pairs. A rare ancestral species therefore has a proportionally smaller influence than a dominant one.

The taxonomy calculation includes pairs of the same species as well as pairs of different species. It is a separate score over the complete compositions; it is not calculated only on the slices left unmatched by species overlap.

7. Combine the two scores

Taxonomy fills a proportion of the compatibility gap left by species overlap:

Base compatibility = overlap + (1 - overlap) × taxonomy
                   = 1 - (1 - overlap) × (1 - taxonomy)

For Aster and Briar:

Species overlap             = 0.35
Remaining gap               = 1 - 0.35 = 0.65
Taxonomy                    = 0.2635
Taxonomy's addition to base = 0.65 × 0.2635 = 0.171275
Base compatibility          = 0.35 + 0.171275 = 0.521275
                            = 52.1275%

Combine overlap and taxonomy

Adding 35% and 26.35% directly would give the wrong result. The taxonomy score adds 17.1275 percentage points here because it applies to the remaining gap.

If overlap is already 100%, taxonomy cannot raise it further. If overlap is zero, base compatibility equals the taxonomy score. If taxonomy is zero, base compatibility equals the overlap.

8. Compare some similar and different ancestries

All rows below show the base score before other breeding modifiers. Fox, Wolf, and Lynx use the example classifications above.

Character A	Character B	Species overlap	Taxonomy	Combined base
100% Fox	100% Fox	100%	90%	100%
100% Fox	100% Wolf	0%	25%	25%
100% Fox	100% Lynx	0%	10%	10%
80% Fox / 20% Wolf	80% Fox / 20% Wolf	100%	69.2%	100%
90% Fox / 10% Wolf	10% Fox / 90% Wolf	20%	36.7%	49.36%
Aster: 80% Fox / 20% Wolf	Briar: 15% Fox / 22.5% Wolf / 62.5% Lynx	35%	26.35%	52.1275%
One game species	A different game species with the same taxonomic species classification	0%	90%	90%
100% one species	100% another species with no shared rank below domain	0%	0%	0%

The inverse 90/10 blends share the same species list but overlap by only 20%. Their taxonomy still helps because Fox and Wolf are related. Its calculation is 0.09 × 0.90 + 0.81 × 0.25 + 0.01 × 0.25 + 0.09 × 0.90 = 0.367.

Identical mixed characters can have less than 90% taxonomy compatibility because the taxonomy comparison includes cross-species pairs inside their mixtures. They still reach 100% base compatibility through exact composition overlap.

9. What if some ancestry has no taxonomy?

A species without a classification still counts toward inherited species percentages and exact-species overlap. Its taxonomy pairs contribute zero.

Suppose U is a known base species that has not been classified:

Character A	Character B	Species overlap	Taxonomy	Base
50% Fox / 50% U	100% Wolf	0%	0.5 × 1 × 0.25 = 12.5%	12.5%
50% Fox / 50% U	100% U	50%	0%	50%
100% U	100% U	100%	0%	100%

The classified half in the first row stays at 50%; it is not enlarged to fill the unclassified half. In the other rows, U is the same actual species on both sides, so it provides exact-species overlap despite having no taxonomy. Two different unclassified species would not match merely because both lack classification.

10. How the base score becomes the breeding compatibility score

The ancestry and taxonomy assessment supplies the base. The complete calculation can also include forced-species compatibility, garden and partner bonuses, and form and class multipliers. Species percentages are not changed by these steps.

Garden and partner bonuses each close up to half of the remaining gap. Form and class multipliers apply afterward. For example, starting with Aster and Briar’s 52.1275% base, assume no forced-species boost and these illustrative modifiers:

Step	Calculation	Result
Base	Inherited species plus taxonomy	52.1275%
Garden bonus of 20%	1 - (1 - 0.521275) × 0.80	61.702%
Partner bonus of 10%	1 - (1 - 0.61702) × 0.90	65.5318%
Form multiplier of 75%	0.655318 × 0.75	49.14885%
Class multiplier of 80%	0.4914885 × 0.80	39.31908%

The species overlap, taxonomy, and combined base are symmetric. A final breeding calculation can differ with context or direction because it also uses those other inputs. A compatibility percentage is also only one part of conception: an available ovum, fertility and other reproductive conditions still matter.

An ovum uses its donor’s ancestry

An ovum may be carried by someone other than its genetic donor. Its species and taxonomy comparison uses the donor’s complete composition and the other character’s complete composition.

An ovum uses its donor’s ancestry

Changing the carrier does not substitute the carrier’s species percentages for the donor’s. The carrier supplies the relevant garden and relationship context, while the ovum supplies its stored form and class.

When the carrier differs from the donor, conception also applies a separate compatibility factor between the ovum and its carrier. That factor is multiplied by the ovum’s compatibility with the breeder. The carrier’s biology therefore still matters, while the donor remains the source of the ovum’s ancestry.

Further reading: Species Compatibility, Creating a Species, and Reproduction and Genetics Lifecycle.